Air pump with means for mounting on water tank



y 1967 D. G. SMITH ETAL 3,

AIR PUMP WITH MEANS FOR MOUNTING ON WATER TANK Filed Aug. 20, 1965 5 Sheets-Sheet 1 INVENTORJ y 8, 1967 D. G. SMITH ETAL 3,

AIR PUMP WITH MEANS FOR MOUNTING ON WATER TANK L INVENTORJ' BY qfg July 18, 1967 D. G. SMITH ETAL AIR PUMP WITH MEANS FOR MOUNTING ON WATER TANK 5 Sheets-Sheet 5 Filed Aug. 20, 1965 INYENTOR s United States Patent 3,331,328 AIR PUMP WETH MEAIQS FOR MOUNTING 0N WATER TANK Dresden G. Smith, San Jose, and Phiilip T. Jones, Los

Altos, Calif, assignors to .l'onesmith (10., Inc, a corporation of California Fiied Aug. 20, 1965, Ser. No. 481,335 (Iiaims. (Cl. 1936) ABSTRACT OF THE DISCLGSURE Air pump mounted on outside of water tank and connected thereto by a pipe for supplying air thereto. Air pump comprises a plate attached to said pipe, said plate having an upright Wall integral therewith. The cylinder of the pump is formed in one end portion of the wall. The piston connecting rod and eccentric assembly are enclosed within said wall. A water level sensor extends through said pipe into the tank. A cover is attached to the top of said wall. A motor is attached to the top of said cover. The motor shaft is attached to a coupling projecting through the cover plate to said eccentric and a shaft is .adjustably supported in a hole in said plate for supporting the eccentric and piston rod so that the piston rod and piston may be aligned with respect to the cylinder.

This invention relates to an air volume control pump unit that mounts directly on the top of the water tank.

An object of this invention is to provide an improved air volume control unit mounted directly on the top of the ;.water tank with which it is to be used, thus minimizing use of external plumbling.

Another object of this invention is to provide an improved air volume control unit mounted directly on the top of the Water tank, said unit being provided with a liquid level switch that is connected to a float in the tank by a flexible cord, thu permitting installation thereof with minimum head room above the tank and permitting rapid changing of the liquid level adjustment.

Another object of this invention is to provide an improved air volume control unit with an air pump that does not require oiling, the air pump being provided with a valve in the piston thereof that doesnt seat until the piston is moving rapidly, thereby permitting the motor driving the air pump to start under substantially no load.

Still another object of this invention is to provide an improved air volume control unit with an air pump hav ing an eccentric for driving the pump, said eccentric having only one mounting bearing in which tolerances contributing to the vertical misalignment of the piston and cylinder are taken up by positioning the stub shaft supporting eccentric mounting up or down to provide the desired alignment and therefore locking this stub shaft in position.

Still another object of this invention is to provide an improved air volume control unit in which the piston of the air pump is provided with a ring having a shoulder that rests directly on a land in the ring groove of the piston whereby the ring pilots the piston in the cylinder of the air pump without requiring the use of a heavy backup spring, or separate centering device, thereby eliminating excessive drag of the ring on the cylinder wall.

Another object of this invention is to provide an improved air volume control unit in which the air pump is driven by a high torque shaded pole AC motor that does not require any centrifugal switches or other starting operating devices.

Another object of this invention is to provide an improved air volume control unit mounted directly on the water tank, said unit being provided with an air pump that is driven by a motor positioned above the air pump in a housing having an air filter positioned under the motor so that the filter is not exposed to dirt which is not actually in the air passing through the filter into the pump.

Another object of this invention is to provide an improved air volume control unit mounted directly on the top of the water tank, said unit being provided with a casting having a tank mounting interface with the electrical junction box provided for the motor of the unit formed integral therewith said interface having the air passages leading from the air pump of the unit to the water tank.

Other and further objects of this invention will be apparent to those skilled in the art to which it relates from the following specification, claims and drawing in which, briefly:

FIG. 1 is a side view of a water tank and pump installation showing the upper part of the water tank partially in section and also showing the air control unit of this invention mounted on the top of the water tank;

FIG. 2 is a veitical sectional view through the air pump and motor unit of this invention showing part of the unit housing and motor cut away;

FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2;

FIG. 4 is an enlarged sectional view of the air pump piston;

FIG. 5- is a sectional view taken along the line 5-5 of FIG. 2, said sectional view being broken away on the top and bottom thereof;

FIG. 6 is a bottom view of the unit shown in FIG. 2 with the cover plate for the junction box recess partly broken away and with one side of the unit also partly broken away;

FIG. 7 is a schematic wiring diagram showing electrical connections employed in this apparatus; and

FIG. 8 is a schematic wiring diagram showing modified electrical connections employed in this apparatus.

Referring to the drawing in detail, there is shown in FIG. 1 a water tank 10 having an outlet pipe 11 and an inlet pipe 12 connected thereto. The inlet pipe 12 is connected to the pump 13 which is driven by the motor 14 to raise water from the well 15 and pump it into the tank 10 through the pipe 12. The upper part of the tank 10 is shown in partial section to expose the mechanism positioned therein. The air volume control unit is positioned in the housing 16 which is supported on the top of the tank 14 by the pipe 17. The pipe 17 is threaded into the casting 23 which forms the bottom part of the housing.

Another pipe 18 which is also threaded into the cast ing 23, as shown in FIG. 2, extends down into the tank 10 and supports the electric switch 19 at the bottom thereof. Switch 19 is provided with an actuating lever 20- that is connected by the flexible cord 21 to the float 22. The upper end of pipe 18 connects with the bore 18a in the casting shown in broken lines in FIGS. 5 and 6, This bore is provided for the electrical connections leading to switch 19. The housing 16 is also provided with a top 16b which hangs over the upper sides of the housing. Holes 16a are provided under the overhanging top in the upper part of the housing and these holes communicate with the space under the top 1611. The lower part of the housing side walls is attached to the casting 23, which forms the housing bottom, by means of suitable screws. Air spaces are provided between the casting 23 and side walls of the housing 16 so that air may circulate up therethrough.

The upper part of the casting 23 is provided with a wall 24 which encloses a cavity in which some of the pump mechanism is positioned, as shown in FIGS. 2 and 5. A cover 25 is provided to the top of Wall 23 and this cover 3 is attached to this wall by suitable machine screws. The motor 26 is supported on the cover by the pillars 27 which are attached to the cover by suitable machine screws.

The left hand end 24a of the wall 24 is provided with a hole large enough to receive the cylinder 28 of the air pump. This cylinder is held in this hole by the flange 29 which extends into the hole and abuts the shoulder 28a of the cylinder. The inner end of the cylinder 28 is beveled, and the O-ring 30 is pressed against this bevel surface to hold the cylinder abutting the flange 29. The inner side of the disc-shaped member 31 abuts the O-ring 30. The member 31 is provided with a hole 32 which extends along a diameter thereof and communicates with the central cavity 33 and the outer ends communicate with the peripheral groove 36.

The ball valve 35, which may be of Neoprene or similar elastomeric materials, is positioned in the cavity 33 and is pressed against the hole 34 by spring 43 which extends into cavity 42 that communicates with cavity 33. The hole 34 extends through the disc member 31 and forms a port between cavity 33 and the cavity in the cylinder 28. The end wall 24a of the casting is provided with a hole 38 bored therethrough so that it extends to the hole 39 also bored in the casting 24-. The upper part of hole 38 is sealed by the plug 37.

The hole 38 is open to the peripheral groove 36in member 31 and it communicates with the hole 39 which extends through the casting 24 from the outside thereof to the cavity 17a into which the pipe 17 is threaded. The outer end of hole 39 is sealed by the plug 40. An O-ring is positioned against the outer side of member 31 and holds this member pressed against O-ring 3G. The plug member 41 is positioned in the outer end of the cylinder hole and the beveled inner edge thereof is held pressed against the O-ring 45 by the strap 44 which is attached to the casting end 24a by machine screws 44a.

The piston 46 of the air pump is made integral with the rod 47 and it is provided with a cavity opening to the inner face thereof for receiving the cup-shaped member 53 in which the valve member 52 is positioned as shown in FIGS. 2 and 4. The piston 46 is provided with a hole 48 which communicates with the recess in the cup 53 and which is adapted to be closed by the valve member 52 during the compression stroke of the piston. The cup member 53 is provided with holes 54 which communicate with the cavity inside of the cup member. The circumference of the piston 46 is provided with a ring groove 49 for receiving the piston ring which is provided with an inner portion 50a that approaches the land of the ring groove. As an example the ring 50 may be made of material such as Rulon which is reinforced Teflon, or carbon. A backup spring 51 is provided to the piston ring to cause the ring 50 to seal against the inner cylinder wall, and this backupspring is just strong enough to cause the ring to seal without causing excess drag thereof on the cylinder wall.

The piston rod 47 is provided with an opening 47a for receiving the ball bearing assembly 56 and the eccentric 55. The outer race of the ball bearing assembly 56 is lodged against the shoulder 47c of the rod 47, and the inner race of this ball bearing assembly is lodged against the shoulder 55a of the eccentric 55. Retaining rings 47]) and 55b are positioned in grooves formed in the rod 47 and eccentric 55, respectively, for engaging the upper surfaces of the ball bearing assembly 56 and retain this assembly in position on the aforesaid shoulders 47c and 55a. The eccentric 55 is provided with a stud 58. The coupling member 57 is attached to the stud 58 by a set screw or the like (not shown). A similar coupling member 59 is attached by a set screw or the like (not shown) to the shaft 26a of the motor 26 which is positioned above the stud 58. The opposing faces of the coupling members 57 and 59 are provided with splines for receiving the splined member 58a, which is made of suitable plastic such as nylon or the like, and serves to couple the mem- 4 bers 57 and 59 whereby the motor 26 may be employed to drive the eccentric 55.

The eccentric 55 is supported on the member 61 by the ball bearing assembly 60. The member 61 is positioned in a hole formed in the casting 23 and is held therein by set screw 610. By adjusting member 61 up and down the eccentric 55 and piston rod 47 may be either raised or lowered, as required for proper alignment of the piston 46 in the cylinder 28. The member 61 is provided with a shoulder 61a on which the inner race of the ball bearing assembly 60 rests and is held thereon by the ring 61b provided in a groove formed in the upper part of the member 61. The eccentric 55 is provided with a shoulder 55c which rests on the upper surface of the ball hearing assembly 6%. A suitable retaining ring 55 is provided in the lower part of the eccentric 55 to retain the eccentric positioned on the ball bearing assembly.

A filter 62 of felt or similar material is positioned under the motor and over the holes 25a formed in the plate 25 so that air drawn into the pump chamber through the holes 25a must pass through this filter material. A cavity 23a is provided in the lower part of the casting 23 for housing the fuse block 63 which receives the fuses that are connected to the electric circuit of the motor 26. This cavity 23:: is covered by the cover plate 23b that is attached to the casting by suitable machine screws.

The wiring diagrams employed for this apparatus are illustrated in FIGS. 7 and 8 in which the same reference numerals used in FIG. 1 are used for corresponding parts. The water pump motor 14 is connected to the supply line through a switch which may be a pressure control switch or a manual switch as desired. The air pump motor 26 is connected to the supply line in parallel with the motor 14 through the fuse block 63 and switch 19 which is mechanically controlled by the float 22.

A modified circuit is shown in FIG. 8 in which the motor 26 is connected to the supply line by the relay 19a. In this circuit the switch 19 controls the energization of the winding of relay 19a and the relay contacts 19b are connected in series with the motor 26. Thus, when the switch 19 is closed, the winding of relay 19a is energized and the contacts 1% thereof are closed so that current is fed to the motor 26 and the air pump operated thereby is driven.

It will be noted that the motor 26 is not capable of being energized unless motor 14 is running. Therefore when water pressure in the tank 10 goes down, the switch 14a is closed, the motor 14 is energized and causes water to be pumped into the tank 10. Normally the air volume in tank 10 is large enough that the water level is low, thus float 22 is down and switch 19 is open. If the air volume in the tank 10 is insufficient, the water level in tank 10 rises due to the pumping effort of water pump motor 14, thus lifting float 22 and closing switch 19 so that the air pump motor 26 is energized and drives the pump to supply air into the tank 10 through the passages 32, 36, 38,. 39, 17a and 17 The piston 46 of the air pump is provided with a valve member 52 which does not seat properly over hole 48 until the piston 46 is moving rapidly in its compression stroke so that the motor 26 starts at substantially no load. When the piston 46 is moving rapidly, the valve member 52 is impacted on the seat around hole 48 during the pressure stroke of the piston, and during the return stroke, the valve member 52 is moved against the bottom of the cup 53. The air entering the cylinder during the return stroke is compressed during the pressure stroke and the compressed air opens valve 35 against the pressure of spring 43. Compressed air is thus supplied from cylinder through hole 34 to the bore 32, passageway 36 and bores 38 and 39 to the pipe 17 through which it flows into the upper part of tank 10. As the piston 46 is reciprocated in the cylinder 28 the piston ring 50 functions to seal the piston to the cylinder. This ring may have a little play in the groove 49 however the forward and rear side of the ring form a seal with the sides of the groove during the return stroke and compression stroke respectively because the piston must press on the ring to move it in the cylinder.

While we have shown a preferred embodiment of the invention, it will be understood that the invention is capable of variation and modification from the form shown so that its scope should be limited only by the scope of the claims appended hereto.

What we claim is:

1. In an air volume control pump for water tanks and the like, the combination of a plate having an inte-gral upright wall thereon, said wall defining a cavity open at the top thereof, a cover for said cavity attached to the top of said wall, a pipe attached to the bottom of said plate supporting said plate on a tank, a sensor attached to said plate into said tank for sensing a predetermined liquid level in said tank, said wall having a cylinder means opening into said cavity, a piston slidable in said cylinder means, a piston rod connected to said piston, an eccentric connected to said piston rod, means supporting said piston rod and said eccentric in said cavity, said means comprising a stub shaft and adjustable means supporting said stub shaft in the bottom of said cavity so that said piston and said piston rod are adapted to be raised or lowered with respect to the axis of said cylinder means, a motor mounted on said cover, said motor having a shaft and means aligned with a hole through said cover connecting said shaft to said eccentric, said plate having an air passage connecting said cylinder means t-o said pipe, and means responsive to said sensor for connecting said motor to a source of current supply when the liquid in said tank is at said predetermined level.

2. In an air volume control pump for water tanks and the like, the combination as set forth in claim 1 further characterized in that said cylinder means comprises a sleeve positioned in an opening through said wall, plug means positioned in said opening and abutting the outer end of said sleeve and detachable means holding said plug means in said opening.

3. In an air volume control pump for water tanks and the like, the combination as set forth in claim 2 further characterized in that said air passage includes an air passage through said plug means, and a spring-loaded air valve positioned in said plug means normally closing the air passage to said cylinder means therethrough.

4. In an air volume control pump for water tanks and the like, the combination as set forth in claim 2 further characterized in that said pl-ug means comprises an inner part which abuts said sleeve and an outer part abutting said inner part, said air passage including an air passage through said inner part, both said inner part and said outer part being sealed into said cylinder means to prevent air leakage past surfaces thereof, and a spring-loaded valve positioned in the air passage through said inner part normally closing this air passage.

5. In an air volume control pump for water tanks and the like, the combination as set forth in claim 1 further characterized in that said piston is provided with a ring of carbon or plastic positioned in a groove formed on the outer surface thereof, said ring having an internal shoulder that is adapted to engage the bottom of said groove, said ring also having an internal recess in which there is lodged a spring pressing outwardly on said ring with a light pressure to prevent scoring of the wall of said cylinder means by said ring.

References Cited UNITED STATES PATENTS 1,917,639 7/1933 Evans 92-200 1,998,338 4/ "1935 Spohrer 23 0-58 2,710,137 6/1955 Arnovil 230-172 2,792,790 5/1957 Capps 103-178 2,819,013 1/1958 Paasche 230-58 2,963,217 12/1960 Wysong 230- 3,049,284 8/1962 Alamprese 230-221 3,073,256 1/ 1963 Brown et al 103-1 53 3,162,130 12/1964 Glisson 103-6 3,175,758 3/1965 Dirk 230-221 3,181,779 4/1965 Rhodes 230-172 'DONLEY J. STOCKING, Primary Examiner. W. L. FREEH, Assistant Examiner. 

1. IN AN AIR VOLUME CONTROL PUMP FOR WATER TANKS AND THE LIKE, THE COMBINATION OF A PLATE HAVING AN INTEGRAL UPRIGHT WALL THEREON, SAID WALL DEFINING A CAVITY OPEN AT THE TOP THEREOF, A COVER FOR SAID CAVITY ATTACHED TO THE TOP OF SAID WALL, A PIPE ATTACHED TO THE BOTTOM OF SAID PLATE SUPPORTING SAID PLATE ON A TANK, A SENSOR ATTACHED TO SAID PLATE INTO SAID TANK FOR SENSING A PREDETERMINED LIQUID LEVEL IN SAID TANK, SAID WALL HAVING A CYLINDER MEANS OPENING INTO SAID CAVITY, A PISTON SLIDABLE IN SAID CYLINDER MEANS, A PISTON ROD CONNECTED TO SAID PISTON, AN ECCENTRIC CONNECTED TO SAID PISTON ROD, MEANS SUPPORTING SAID PISTON ROD AND SAID ECCENTRIC IN SAID CAVITY, SAID MEANS COMPRISING A STUB SHAFT AND ADJUSTABLE MEANS SUPPORTING SAID STUB SHAFT IN THE BOTTOM OF SAID CAVITY SO THAT SAID PISTON AND SAID PISTON ROD ARE ADAPTED TO BE RAISED OR LOWERED WITH RESPECT TO THE AXIS OF SAID CYLINDER MEANS, A MOTOR MOUNTED ON SAID COVER, SAID MOTOR HAVING A SHAFT AND MEANS ALIGNED WITH A HOLE THROUGH SAID COVER CONNECTING SAID SHAFT TO SAID ECCENTRIC, SAID PLATE HAVING AN AIR PASSAGE CONNECTING SAID CYLINDER MEANS TO SAID PIPE, AND MEANS RESPONSIVE TO SAID SENSOR FOR CONNECTING SAID MOTOR TO A SOURCE OF CURRENT SUPPLY WHEN THE LIQUID IN SAID TANK IS AT SAID PREDETERMINED LEVEL. 